(1) Field of the Invention
The present invention relates to an optical function semiconductor device provided with a semiconductor light emitting diode for presenting various functions between an input light and an output light thereof, particularly, so as to realize an optical function device which can be readily miniaturized and integrated and further furnishes a basis for the optoelectronics.
(2) Description of the Prior Art
In the field of optical industrial techniques including the optical communication, the optical information transmission, the optical data processing system and the like, various kinds of semiconductor devices which utilize the electro-optical effect and the acousto-optical effect for the high speed control of the light have been developed hitherto. However, most of these conventional optical function semiconductor devices are arranged for controlling the light passing therethrough by an electric voltage or an electric current applied to an element presenting the electro-optical effect or the acoustical-optical effect, so that these conventional devices cannot be regarded as a genuine optical device which is operated in the situation between an input light and an output light.
On the other hand, a bistable optical element, that is, a so-called BOD, which has been vigorously developed recently, is known as a kind of optical function device. This BOD is a new light input to light output device of high speed operation and low power consumption which is arranged for being controlled by feeding back an electric voltage or an electric current thereto, which is proportional to an output light intensity thereof obtained in a situation where it is used as an optical switch, an optical modulator or the like. Accordingly, this BOD is intended to be utilized for an optical differentiating amplifier, an optical switch, an optical limiter, an optical pulse shaper, an optical memory, an optical operator and the like, and hence has been already developed in various forms such as a Fabry-Perot resonator of genuine type including a nonlinear medium or an optical modulator of hybrid type which is controlled by electrically feeding back. However, all of these conventional bistable optical devices are no more than passive elements containing no light source which is indispensable for the operation thereof, so that is is an indispensable condition to be combined with an external light source. Consequently, these conventional optical function semiconductor devices have a significant essential defect which impedes the miniaturization, the simplification and the integration as the most requirement for practical use of the optical function device of this kind.
As a drastic remedy for the above defect of the conventional bistable optical device, the present inventors proposed a laser functional device by U.S. patent application Ser. No. 361,816, which device included a semiconductor laser element as a light source and was effected the bistable operation under the combination with an opto-electrical converting element. In relation thereto, the semiconductor laser has recently made a rapid progress and the performance thereof has been remarkably improved. As a result, it is provided with favorable benefits such as it is ready to be formed as an extremely minuscule laser element and to be excited by an electric current and further to be integrated in combination with another electronic or optical device. However, on the other hand, it is also provided with various difficulties in practical use such as the range of the wavelength of the emitted light and hence an arbitrary wavelength are difficult to be set up, the structure thereof is comparatively complicated and hence it is not so easy to fabricate it with a low cost.